Thekmostatic control means



July 8, 1941. f c. R. MUELLER I THERMOSTATIC CONTROL MEANS Filed Dec.17, 1936 .alllllllllllllllllllll/ Patented July 8, 1941 UNlTED STATES,PATENT OFFICE THERMOSTA'IIC CONTROL MEANS Christian R. Mueller, HighlandPark, Mich. Application December 17, 1936, Serial No. 116,438

1 Claim.

This invention relates to improved thermostatic control means, theprincipal object being the provision of structures that are simple inconstruction, efficient and positive in operation, and economical toproduce.

Further 'objects of the invention include the provision'of a novel formof thermostat structure adapted to be controlled by the temperature ofthe cooling medium for the engine of a motor vehicle; the provision of athermostat structure adapted to be controlled by the temperature of thecooling fluid of an internal combustion engine and so constructed andarranged as to be quickly responsive to changes in the temperature ofthe cooling medium without obstructing the flow of the cooling mediumthrough the regularly provided passages therefor; the provision of athermostatic structure for use in connection with internal combustionengines including a bulb and av water passage for the cooling huid ofthe engine, the two being formed as a unit whereby to facilitate thetransfer of heat between them; the provision of a thermostatconstruction for motor vehicles having a fluid cooling system including'abulb and a water passage element, the

element being adapted for Vinsertion in the fluid circulating system ofthe engine and being formed as a unit with the bulb; the provision of athermostat structure for controlling a motor which are in heatconducting relation with respect to the cooling fluid 'of the enginethrough a metallic wall, and which is so constructed and arranged as topermit lling of the bulb at atmospheric pressure, the filling of whichbulb is relatively insensitive to variation of lling liquid therein, andin which the filling fluid may be any one of vrelatively cheap andcommonly known liquids such as ethyl or methyl alcohol or gasoline; theprovision of a thermostat structure i l adapted for insertion in thehose connecting the cooling jacket of an internal combustion engine withits cooperating radiator, and in which rapid. transfer of heat betweenthe cooling medium and restricting vthe flow of the cooling mediumthrough the hose; and the provision of a thermostat structure for motorvehicles and the like Vhaving an internal combustion engine and acoolvehicle part including a bulb" the contents of f3.0

the contents of the bulb is providedA for Without :14 5

ing `radiator including a thermostatic bulb and tion in the usual hoseconnecting the cooling Vjacket of the engine with the radiator and so'means cooperating therewith adapted for inser- Y immediately electiveto temperature changes in the cooling fluid passing through the hose.

AThe above being among the objects of the present invention the sameconsists in certain novel features of construction and combinations ofparts to be hereinafter described with reference'to the accompanyingdrawing, and then claimed, having the 'above and other objects in View.

In the drawing which illustrates suitable embodiments of the presentinvention and in which like numerals refer to like parts throughout theseveral dilerent views,

Fig. 1 is a partially broken sectional view'taken centrally through apreferred form of expansible bellows structure 'preferably employed in`the thermostatic control of automobile radiator shutters according tothe present invention;

' Fig." 2 is a lsectional view taken centrally through the thermostaticcontrol bulb and associated cooling passage of the thermostatconstruction employed for controlling the operationof the bellows shownin the preceding view; and

Figs. 3 and 4 are views similar to Fig. 2 but showing modied-forms ofconstruction.

In accordance with conventional-practice radiator shutters have beenthermostatically controlled either by the employment of a thermostaticelement positioned in the path of flow of air passing through thecooperating radiator or else have been placed directly in the radiatorheader. In the former practice the transfer of heat between the coolingmedium for the engine and the thermostat isso slow that a considerablelag in the operation of the shutter results with consequentdisadvantages and in the latter practice it requires specialconstruction of the radiatorA header; introduces complications into theconstruction of the same and is liable to leakage about the line ofvjunction between the thermostatic element and the radiator header. Inaccordance -with the present invention the thermostatic element foroperating the radiator shutters is so constructed and arrangedas topermit it to 'be quickly and easily inserted vin any existingtemperature of the cooling medium flowing through such hose.Additionally the construction of the thermostatic portion of the deviceis such as to permit it to use cheap and common liquid as either ethylor methyl alcohol or gasoline as the actuating uid in the thermostat anddoes not require accurate or a predetermined degree of lling tothereafter insure the proper and satisfactory operation of the device.

According to the present invention a novel form of thermostatic means isemployed which is particularly adapted for controlling the operation ofthe shutters. Brcadly this thermostatic means comprises a bellows unitindicated generally as at ld, a bulb' unit indicated generally at |56,and a tube H28 inter-connecting the bellows unit and bulb unit. Thebellows unit |04 is preferably rigidly secured to the frame 25 andincludes an axially movable rod In adapted to be suitably connected tothe bar 94 to actuate the same against the force of the springV |942.The4 form of connection between the rod |||l` and the barV 94 may be ofany suitable construction and'will depend to some extent upon theposition in which the bellows assembly l'dis secured to the frame thelatter position being governed primarily by the available space for itand theV matter of convenience.

The bellows assembly IM may be suitably secured-to a suitable frameportionof the vehicle with therod Hlthereof projecting downwardlytherefrom. It is to be understood thattherod I6 is connected to theshutters through suitable operating mechanism so that'l the shutters arepivoted about their axes upon expansion'and contraction of the bellows.

Referring now to Fig. l it will be noted'that the bellows assembly llllcomprises a housing having removable ends |22 and |24; respectively.

VPositioned within the housing Iii]VV and suitably fixed. to the endIl'is a metal bellows |25. The free end of the bellows |2515` providedAwith a stem |23 suitably guided'for axialmovement in a sleeve |38fixedV in the end wall |22. The rod Hl is suitably securedto the stem|28,as by threading or the like soas to receive romthe stem |23 equalaxial movement therewith. A connection |32. communicating with theinterior of the bellows.V |`I projects through the Wall `|24 Aand onYthe upper side of the wall`l24i's provided with-a nut |24 serving toremovably clampv it to the wall |24. The tube IliB is connected'to theconnection liiinV any suitable manner such for instance as by means of aconventional'type of compression coupling.

t Referring nowv to Fig.. 2 the bulb assembly |95 comprises a hollowcontainery I'lprovided'with a removable plug |42 in itsV upperend'wall'a'nd at its lower end provided with a connection |44communicatingthe interior of the tube |8` to the interior of .thecontainer |40. It will .beunderstood that in practice the interior ofthebellows |26, tube |08 and container |40 is-lled or substantially filledwith Yasuitable expandable or `vaporizlable liquid. It is notessentiaLhowever, that the entire available volume ofy these parts becompletely lled withfsuch fluid and infact it hasbeen found preferableto leave* a small amount of air such as indicated at Idlinlig. 2 abovethe level of the uid IlBin the bulb for therpurpose of eecting actuationofthe bellows |26.

As will be understood by those skilledin the art the fluid Hi8 in thebulb assembly |06 is adapted to be positioned in h'eat transferringrelation with respect to the cooling fluidlior. the internal combustionengine to which the shutter mechanis'mis adapted, andiwlienthetemperature of such cooling fluid reaches a predetermined high limit theexpansion or partial vaporization of the uid |48 will set up a pressurewithin the thermostatic system which will cause expansion of the bellows|26 and movement of the rod and consequent opening of the shuttermechanism against the force of a spring to permit the temperature of thecooling uid to'be reduced. TWhen the pressure in the thermostatic systemis reduced through cooling of the fluid medium the pressure of a springwill cause lthe shutter to be closed a corresponding l amount.`

As previously explained it has been conventional practice to eitherposition the thermostatic element fora radiator shutter in the path ofilow of air' passing through the radiator, in which case the action offthe radiator shutter is relatively sluggish and lags behind the changesin temperature of the cooling fluid, or to position the thermostaticelement directly in the header of the cooling radiator in which case theradiator must be especially constructedtoireceive it and renders theradiator liable tov leaks. In either case the heat exchange-between the'cooling medium forV the f eng-ine and the4J thermostat must usually takeplace through a body of air'whicli inand of itself bein-ga-relativelygood heat insulator, detracts-from'tlierspeed of operationof thefdevice.

disaclvantager ofi conventio'nal'-r constructions-iseliminated 'in'accordance 'with the `presentf invention by-fprcvidilngf fortl'ievtransfer of heat-between theY coolingfmedium andthe uid |48 inthe bulbassembly- Ib'fthi'oughhighlyheat conducting metal walls ratherthanthrougli air, andso constmctin'gtlfe'devicethat this may'beaccomplished lwithout any special 4construction of the cooling-systemforthe engine and :permitting the application'of thepresentpinvention'to" any existingr engine structure-in a quick'andecient way which will. inot-obstructthefreezlow' of cooling medium 1through the engine vcooling system. Specifically this isaccomplished. inthe construction-*shown-in Fig. 2by'providing a. sleeve |5D integrallylformediora'tleastjdirectly but metallically-connected to 'the'contain'er'll 'but *laterally spaced there-from; *In-Fig.' 2"'tlie1sleeve |50 isshown as bei-ng ycast integrally with the container |40 and -as beingIconnectedthereto through an integral arm-|52: 'Iliesleeve |50 is of suchd'- rnension *asl to be insertable"intliefusual hose 52| conventionallyemployed` inl motor vehicles to connect tlie outlet vfrom the cooling-jacket .o'f .the engine 4| 55-with the cooling radiator upper header.To insert the sleeve".|5U"thereintoall thatis poi-nt and Ltheninsert'the,oppositeendsofthe sleeve |50-into the"adjacentends voftlielios'e, 5i providedby` suchV cutting.' Conventional clamps I 5t lare'preferablyprovided for insuring a waterv of the. container MDV. In..this respect it will be noted that the sleeve |50'. serves.. as. heatconductnginson the armor neck I'SZand-materialcontainer MU'anditscontents and the water flowing through the hose |54. vIt has been foundthat the transfer of heat through a construction substantially identicalto that shown in Fig. 2 and formed of aluminum is so rapid and causesthe uid content |48 of the container |40 to respond so quickly tovariations in change of the temperature of the water flowing through thehose |54 that when operating a radiator shutter of the type previouslyydescribed it is capable of maintaining the temperature of the coolingwater for the enginel within a plus or minus 3 F. of the desiredtemperature over la wide variation of engine speeds and loads.

As has been previously mentioned the fluid content |48 of the container|40 and also the tube |88 and bellows |26 may be one of such commonliquids such as methyl or ethyl alcohol or gasoline. When filled withethyl alcohol the radiator shutter will be operated to hold thetemperature of the cooling water of the engine at substantially 170 F.Methylalcohol when employed will hold the temperature of the coolingWater at substantially 160 F. and rst grade gasoline at 150 F. Othertemperatures can, of course,

-be maintained by employing one or more other suitable liquids orcombination of liquids and the operation of the shutter may also beeffected to some extent by changing the tension of the spring |02. Thecontainer |40 and its connected tube |68 and bellows |26 may be lled atatmospheric temperature and at atmospheric pressure with any of theabove described liquids and as previously described the degree offilling of the container |40 is more or less unimportant as long asthere is a material amount of the liquid |48 therein It will, of course,be understood that the container |40 may be positioned in any suitableor convenient relation with respect to the sleeve |50 but in any eventit will be advisable that the actual point of connection of the tube |88with. the interior of the container |40 is adjacent the bottom of thecontainer.

In Fig. 3 a modification of the construction shown in Fig. 2 isillustrated. In this modiiication the bulb assembly |06 is formed fromsheet metal and the construction is further modified to provide for thedirect circulation of the cooling fluid for the engine owing through thehose |54' directly around the container |40' for the thermostatic iiuid|48. In this case the container |40 has a mean body portion |60 formedfrom a length of metal tubing and an upper and lower head |62 and |64respectively suitably secured and sealed to the main body portion |60. Aremovable filler plug |42 is provided in the upper head |62 andcorresponds to the plug |42 in the construction shown in Fig. 2. In thismodification instead of connecting the tube |08', corresponding to thetube |08 in Fig. 2, into the side of the container it is connected intothe container through the bottom wall |64 by means of a suitable fitting|44. In order to connect the container |40 with the sleeve portion ofthe device a pair of sheet metal stampings |66 and |68 are provided.These stampings |66 and |68 are provided with inturned marginal flangeswhich nest within each other to space the main body portions of themembers |66 and |68 from each other so as to form a hollow structure.Each of the stampings |66 and |68 adjacent but spaced from one endthereof is provided with an outwardly turned ange |10 of a size andshape to closely receive the main body portion |60 of the container |40'therein. Similar flanges |12 are provided adjacent the opposite end ofthe stampings |66 and |68 and each of the flanges |12 receive therein ashort length of tubing |14, the length of tubing |14 cooperating withthe corresponding anges |12 to provide a sleeve structure, such as thestructure |50 previously described, for reception in the hose |54', Thejoints between thevarious parts of the mechanism thus described are, ofcourse, carefully soldered or otherwise sealed so as to render themtight against leakage.

' It will be understood that with the construction shown in Fig. Y3 apassage is provided between the members |66 and |68 which extendscompletely a'round the container |06 and is in open communication withthe interior of the hose |54 so that when the engine cooling fluid isflowing through the hose |54 it will have more or less of a tendency tocirculate directly 'around the container |40 so as to eiect a rapidtransfer of heat between the uid |48 in the container |40' and theengine cooling fluid.

Should it be desired to provide a positive circulation of the enginecooling uid flowing through the hose |54 through the passage formedbetween the members |66 and |68 and around the container |40', when themembers |66 `and |68 are assembled a dividing wall member may beinserted between them. The member |80 may have marginal ears such as |82struck in opposite directions therefrom to maintain it centrally of thepassage between the members |66 and |68 and if desired it may be formedto encircle the container |40' so that even though it may be more orless loose in its position it is held 'against material displacement.The member |80 may have a lip |84 thereon projecting into intersectingrelation with respect to the stream of cooling fluid owing through thesleeve portion of the device and inclined towards the direction fromwhich the flow is received so as to deflect a portion of such flowinwardly through the `passage between the members |66 and |68 around thecontainer |40 and then up over the wall |80 and back into the main flowstream through the hose |54'. In this manner a positive circulation ofthe cooling fluid flowing through the hose |54' directly against thecontainer |40' is assured and consequently any tendency of thethermostaticr means to lag behind changes of temperature in the coolingfluid of the engine is effectively and efficiently eliminated.

In Fig. 4 a construction similar to that shown in Fig. 3 is illustratedbut embodies certain modifications not shown in either Fig. 2 or Fig. 3.In thiscase the container |40" is constructed in the same manner as'thecontainer |40 in Fig. 3 with the exception that the lower wall |64' isimperforate and the tube |08 is introduced through the top wall |62 ofthe container |40, but in order to insure flow of liquid into the tube|08" from the bottom of the container the tube |08" is provided with anextension |86 within the container |40" which extends downwardly throughthe container to a point adjacent the lower Wall |54 thereof. In thiscase members |66 and |68 corresponding to the members |66 and |68 inFig. 3 are provided and are secured to the container |40 in a simliarmanner except that the flanges |10' are formed at one end of the membersfor reception of the container |40" instead of spaced from such ends asin the construction shown in Fig. 3. Addition-ally the wall of thecontainer |40" is cut away as at |88 to provide free. communicationbetween the interior of the container 148'/ andzthe spaces-between-themembers itt. and IS8'. Also: insteadV of 'using the short length-of:tubing such as the parts=l14 in Fig. 3, a singletlength'oftubing: |9is;pro. jected through both-,flanges |12 toiform` the sleeve portion ofthe device andiconsequently the piece of'tubing |90 seals the flow` offluid through thehose |54 from thespa-ce between the members 166 andi682 Itwill be observed that in this construction the thermostatic iiuidi485 not only lls the interior of the container 54% but alsothevspacebetween the members 56 and 68 and consequently surrounds, thesleeve i953 throughwhich` the4 cooling uidfor therengine flows.Thezresult of thisconstruction is,.of course, substantially equivalentto that shown in Fig. 3.

Formal changes may be made inlthe specific embodiment of the inventiondescribed without departing from the spiritv or. substance r01E; thebroad invention, the scope of` which is. com mensurate with the appendedclaim.

y What Ielaim is:

Athermostatic-control means responsive to the temperature of a fluidflowing through a hose of afcoolingsystem :comprising a bellows, athermostatic; bulb arranged in: adjacent relationship to said hose and.operatively connected `to said bellows; and a'volatile fluid in saidbellows and bulb, the: combination of =a metallic sleeve 0f relativelyaxially; extendedlength inserted inl said hose between adjacentl ends ofadjacent sections thereof'formingVmeans-for clamping said ends iniiuidetight relation to each other and withthe interior surface of saidsleeve exposed to'the direct flow of water therethrough, an armconnected with 'said sleeve in intimate heat exchange relation-shintherewith intermediate the ends thereof` projectinglaterallytherefrom iand connectedfto-said bulb in intimate heatA exchange relationshiptherewith, said arm being of substantial cross-sectional congurationwhereby to eiectarapidrtransfer-of heat between "said water inzsaidhoseand said volatile fluid in said bulb.

CHRISTIAN R. MUELLER.

